U.S. patent number 6,105,776 [Application Number 09/119,017] was granted by the patent office on 2000-08-22 for pack of articles packaged using a plastic film and process for the manufacture of the plastic film.
This patent grant is currently assigned to Soparil SA. Invention is credited to Daniel Meilhon.
United States Patent |
6,105,776 |
Meilhon |
August 22, 2000 |
**Please see images for:
( Certificate of Correction ) ** |
Pack of articles packaged using a plastic film and process for the
manufacture of the plastic film
Abstract
A pack of articles (2) packaged using a plastic material film
(3) having a preferred direction of tearing (D), a plurality of
articles (2) being disposed side by side in one or more superposed
layers, the film being folded over along a winding direction (E)
around the articles which it retains, opening means being provided
on the film to facilitate the tearing thereof. The means for
opening the film (3) comprise a continuous zone of weakening (A),
which zone is oriented transversely to the preferred direction of
tearing (D), and forming a band (6) which surrounds the pack, this
zone of weakening (A) having a mechanical strength which is
sufficiently high to bear the traction stresses exerted on the film
to retain the articles, but sufficiently low to permit opening of
the film, without a tool, at any point whatsoever of the zone.
Inventors: |
Meilhon; Daniel
(Sort-En-Chalosse, FR) |
Assignee: |
Soparil SA (FR)
|
Family
ID: |
9509571 |
Appl.
No.: |
09/119,017 |
Filed: |
July 20, 1998 |
Current U.S.
Class: |
206/497; 206/432;
383/201; 229/87.05; 428/34.9 |
Current CPC
Class: |
B65D
75/5844 (20130101); B65D 75/58 (20130101); B65D
71/08 (20130101); Y10T 428/1328 (20150115) |
Current International
Class: |
B65D
75/52 (20060101); B65D 71/00 (20060101); B65D
75/58 (20060101); B65D 071/08 (); B65D 065/28 ();
B65B 021/00 () |
Field of
Search: |
;383/201,908 ;229/87.05
;206/432,497 ;428/34.9 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Gehman; Bryon P.
Attorney, Agent or Firm: Millen, White, Zelano
&Branigan, P.C.
Claims
What is claimed is:
1. A pack of articles, wherein the articles are one of cans of
food, canisters, and bottles, the pack being packaged using a
plastic material film (3) having a direction of tearing (D)
therein, a plurality of said articles (2) being disposed
side-by-side in at least one superposed layer, the film being
folded over along a winding direction around the articles, a
continuous zone of weakening (A) to facilitate tearing the plastic
material film (3) by a tongue (J) displaced therefrom for pulling
in a direction transverse to the direction of the continuous zone
of weakening, the zone of weakening being oriented transversely to
the direction of tearing (D) and forming a band (6) which surrounds
the pack, the zone of weakening (A) having a mechanical strength
which is sufficiently high to bear traction stresses exerted on the
film to retain the articles, but sufficiently low to permit opening
of the film without a tool at any point whatsoever in the zone.
2. The pack of articles as claimed in claim 1, wherein the
continuous zone of weakening (A) is perpendicular to the preferred
direction of tearing (D).
3. The pack of articles as claimed in claim 2, wherein the
continuous zone of weakening (A) comprises at least one line (7) of
perforations (8).
4. The pack of articles as claimed in claim 3, wherein the
continuous zone of weakening (A) comprises a central line (7) of
perforations which is surrounded by two parallel lines (9, 10) of
perforations spaced from the central line, and in which the
distance (f) between two successive perforations is greater than
the distance (g) between two successive perforations (8) of the
central line.
5. The pack of articles as claimed in claim 4, wherein the distance
(f) between two successive perforations (11a, 11b ) of the outer
lines (9, 10) is equal to twice the distance (g) between two
perforations of the central line.
6. The pack of articles as claimed in claim 5, wherein the
perforations (11a, 11b) of the two outer lines (9, 10) are aligned
with a perforation (8) of the central line along a direction
orthogonal to the central line.
7. The pack of articles as claimed in claim 6, therefor and wherein
the plastic material packaging film (3) is a two-layer film, the
direction of tearing (D) of which is perpendicular to the direction
of extrusion (E).
8. The pack of articles as claimed in claim 7, wherein the film (3)
is an ionomeric coextruded polyethylene film, comprising therefor
at least one layer of polyolefin and at least one layer of an ionic
copolymer.
9. The pack of articles as claimed in claim 6, wherein the lines of
perforations have a spacing of 5 to 30 mm, over a width of 30 to
100 mm.
10. The pack of articles as claimed in claim 9, wherein the zone of
weakening (A) of the film covers over a succession of empty spaces
(13) between the articles (2).
11. The pack of articles as claimed in claim 10, wherein the zone
of weakening (A) of the film is provided halfway across the width
of the film (3).
12. The pack of articles as claimed in claim 4, wherein the lines
of perforations have a spacing of 5 to 30 mm, over a width of 30 to
100 mm.
13. The pack of articles as claimed in claim 1, wherein the
continuous zone of weakening (A) comprises a central line (7) of
perforations which is surrounded by two parallel lines (9, 10) of
perforations spaced from the central line, and in which the
distance (f) between two successive perforations is greater than
the distance (g) between two successive perforations (8) of the
central line.
14. The pack of articles as claimed in claim 1, wherein the plastic
material packaging film (3) is a two-layer film, the preferred
direction of tearing (D) of which is perpendicular to the direction
of extrusion (E).
15. The pack of articles as claimed in claim 1, wherein the zone of
weakening (A) of the film covers over a succession of empty spaces
(13) between the articles (2).
16. The pack of articles as claimed in claim 1, wherein the zone of
weakening (A) of the film is provided halfway across the width of
the film (3).
17. A plastic material film tightly packing articles in a pack
having a direction of tearing (D), which comprises a continuous
zone of weakening (A), which zone is oriented transversely to the
direction of tearing (D), wherein the zone of weakening (A)
provides a tongue (J) for pulling in a direction transverse to the
zone of weakening.
18. The plastic material film as claimed in claim 17, wherein the
continuous zone of weakening (A) comprises three lines of
perforations (7, 9, 10) comprising a central line (7) in which the
perforations (8) have a smaller spacing and two outer lines (9, 10)
which are parallel to the central line (7) and disposed on either
side.
19. A process for preparing a plastic material film as claimed in
claim 18, wherein the perforations (8, 11a, 11b) are formed in the
course of the unwinding or of the winding of the film (3) before
packaging along its entire length at the time of extrusion,
rewinding, printing or on a tight packing machine for packing
articles.
20. A process for preparing a plastic material film as claimed in
claim 17, wherein the perforations (8, 11a, 11b) are formed in the
course of the unwinding or of the winding of the film (3) before
packaging along its entire length at the time of extrusion,
rewinding, printing or on a tight packing machine for packing
articles.
21. A package of articles comprising:
an array of abutting articles,
a plastic film material wrapped around the articles in a selected
direction of wrapping and having traction stresses therein oriented
in the selected direction,
a continuous zone of weakening extending in the selected direction
of wrapping to provide selectable sites therewithin for rupturing
the plastic film, and
a zone of tearing in the plastic film extending externally of the
zone of weakening at a location beginning at one of the sites
selected for rupturing the plastic film to provide a tear strip in
the plastic film for opening the package by pulling the tear strip
transverse to the zone of weakening.
22. The package of claim 21, wherein the articles are selected one
cans, canisters or bottles.
23. The package of claim 22, wherein there are spaces between the
articles defined by gaps where the articles do not abut.
24. The package of claim 23, wherein the sites for rupturing the
plastic film occur at spaces in the film between areas of the film
abutting the articles.
25. The package of claim 23, wherein the zone of weakening is
defined by a linear array of perforations.
26. The package of claim 21, wherein the zone of weakening is
defined by a linear array of perforations.
27. The package of claim 26, wherein the plastic film material is
heat shrunk around the articles and held thereagainst by traction
stresses.
28. The package of claim 21, wherein the articles are one of cans,
canisters or bottles stacked in a rectangular array with spaces
therebetween defined by gaps where the articles do not abut;
wherein the plastic film is heat shrunk around the articles and
wherein the zone of tearing extends perpendicular to the zone of
weakening.
29. The package of claim 28, wherein the zone of weakening is
created by a linear array of perforations.
30. The package of claim 29, wherein the zone of weakening extends
around the package over the tops and bottoms of the articles and
wherein there are openings in the plastic film at opposite ends of
the package.
31. The package of claim 30, wherein the openings are oval.
32. The package of claim 21, wherein the plastic film material
comprises at least one layer of polyolefin and at least one layer
of an ionic co-polymer.
33. The package of claim 32, wherein the plastic film material
comprises an ionomeric coextruded polyethylene film.
Description
FIELD OF THE INVENTION
The invention relates to a pack of articles, such as cans of food,
canisters, bottles, etc., packaged using a plastic material film
having a preferred direction of tearing wherein, a plurality of
articles is therefor disposed side by side in one or more
superposed layers with the film being folded over along a winding
direction around the articles which it retains and with, opening
means being provided on the film to facilitate the tearing
thereof.
BACKGROUND OF THE INVENTION
Such a pack is prepared in a known manner by tight packing of the
group of articles. The tight packing consists in surrounding the
set of articles to be packed up with a heat-shrinkable plastic
material film, in particular with a heat-shrinkable polyethylene
film. The envelope formed with the film is welded on the edges
which overlap in such a manner as to form a sleeve around the
articles grouped together. The retention of the articles may be
achieved, for example, by the effect of the heat which causes the
tightening of the film around the articles which it envelops. The
two open ends of the sleeve shrink to form at the two ends of the
pack an opening of oval shape, generally referred to as a
crescent.
The opening of the pack and the removal of the articles present a
problem.
It is, in fact, desired to avoid the use of a sharp-edged tool,
which is not always available immediately when it is desired to
remove one of the articles, and which, moreover, runs the risk of
damaging the articles and/or of causing a poorly controlled tearing
of the film, releasing a number of articles greater than that
desired.
A solution already proposed by EP-A-0537079 consists in providing
as opening means tongues, for example of rectangular shape, the
major dimension of which is oriented parallel to the preferred
direction of tearing, these tongues being precut along their two
long sides and one short side. Such tongues are constructed by
indentations of"punch" type, at positions which are spaced from one
another.
While constituting an advance, this solution exhibits a plurality
of disadvantages, in particular the discontinuous construction of
these indentations, as well as the limitation of the choice of the
opening locations which must correspond to these tongues.
The principal object of the invention is to provide a pack of
articles, in which pack the means for opening the plastic material
film permit an easy and controlled opening of the load constituted
by the pack of articles at a number of points which is as large as
possible, in such a manner as to enable the user to choose the
place which is the most appropriate for forming each opening.
SUMMARY OF THE INVENTION
According to the invention, the pack of articles is defined in that
the means for opening the plastic material film comprise a
continuous zone of weakening, which zone is oriented transversely
to the preferred direction of tearing, and forming a band which
surrounds the pack, this zone of weakening having a mechanical
strength which is sufficiently high to bear the traction stresses
exerted on the film to retain the articles, but sufficiently low to
permit opening of the film, without a tool, at any point whatsoever
of the zone.
Advantageously, the continuous zone of weakening is perpendicular
to the preferred direction of tearing.
Preferably, the continuous zone of weakening comprises at least one
line of perforations, in particular regularly spaced.
Advantageously, the continuous zone of weakening comprises a
central line of perforations which is surrounded by two parallel
lines of perforations, spaced from the central line, and in which
the distance between two successive perforations is greater than
the distance between two successive perforations of the central
line. Preferably, the distance between two successive perforations
of the outer lines is equal to twice the distance between two
perforations of the central line.
The perforations of the two outer lines are advantageously aligned
with a perforation of the central line along a direction orthogonal
to the central line. The patterns created by the perforations thus
have the shape of an I.
The plastic material packaging film is preferably a two-layer film,
the preferred direction of tearing of which is perpendicular to the
direction of extrusion. The film is, in particular, an ionomeric
coextruded polyethylene film. Such a film may be constituted by at
least one layer of polyolefin and at least one layer of an ionic
copolymer.
The lines of perforations may have a spacing of 5 to 30 mm, over a
width of 30 to 100 mm.
The invention likewise relates to a plastic material film for the
tight packing of packed articles, this film having a preferred
direction of tearing and being defined by the presence of a
continuous zone of weakening, which zone is oriented transversely,
in particular perpendicularly, to the preferred direction of
tearing.
This continuous zone of weakening comprises at least one line of
regularly spaced perforations, and preferably at least three lines
of perforations, that is to say a central line in which the
perforations have a smaller spacing than in two outer lines which
are parallel to the central line and situated on either side, the
perforations of the central line and of the outer lines preferably
forming I-shaped patterns.
In the case of a plastic material film the preferred direction of
tearing of which is perpendicular to the direction of extrusion, a
process for the preparation of the film consists in forming the
perforations in the course of the unwinding or of the winding of
the film before packaging, along its entire length, in particular
at the time of extrusion, rewinding, printing or on the tight
packaging machine, by a device constituted by needle rollers with a
counterpart in the form of a cylindrical brush. The plastic
material film to be perforated passes between the needle roller and
its counterpart.
This operation may be repeated over the width of the film, having
regard to the final use, in order to create a plurality of
continuous zones of weakening which are parallel to one another, in
the direction of the length of the film.
Apart from the arrangements set forth hereinabove, the invention
consists in a certain number of other arrangements to which more
explicit reference will be made hereinbelow in connection with a
particular embodiment described with reference to the accompanying
drawing, but which is no sense limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 of the drawing is a diagrammatic perspective view of a pack
of articles according to the invention.
FIG. 2 finally, is a top view, on a larger scale, of a part of the
pack of FIG. 1.
DETAILED DESCRIPTIONS
Referring to FIG. 1 of the drawing, a pack 1 of articles 2
comprises cans of food, canisters or the like, packaged using a
plastic material film 3, which is generally transparent. A
plurality of articles are disposed side by side, in two superposed
horizontal layers in the example shown in FIG. 1. A board 4, in
particular of cardboard, separates the two layers.
The film 3 has been folded over along a winding direction E to form
a sleeve around the load constituted by the articles 2. The edges
of this sleeve which are perpendicular to the direction E are
welded to one another.
Generally, the arrangement of the articles forms globally a
rectangular parallelepiped, the long sides of which are
perpendicular to the winding direction of the film. The open ends
of the sleeve formed around the package correspond to the small
faces of the parallelepiped.
The film 3 is subjected to a heat treatment causing the tightening
thereof around the articles 2 in such a way that the open ends of
the sleeve likewise tighten to form oval openings 5, or crescents,
substantially at the center of each small end face of the
parallelepiped.
The film 3 exhibits a preferred direction of tearing D parallel to
the long sides of the parallelepiped.
The film 3 is advantageously constituted by a film comprising at
least two layers. The film is formed of at least two thermoplastic
resins, and the preferred direction of tearing D of the film is
substantially perpendicular to the direction of extrusion E which
is the same as the winding direction. The film is, in particular,
formed of at least one layer of polyolefin and at least one layer
of an ionic copolymer. The film is, for example, an ionomeric
coextruded polyethylene film. A film according to EP-A-0537080 is
particularly suitable.
The pack 1 comprises opening means constituted by a continuous zone
A of weakening of the film 3, which zone is oriented transversely,
preferably perpendicularly, to the preferred direction of tearing D
of the film. The zone A forms a band 6 which surrounds the pack on
four faces of the parallelepiped.
In the example shown in FIG. 1, a single band 6 is provided,
halfway along the large faces of the parallelepiped, that is to say
halfway across the width of the film 3. Depending on the
requirements, it is possible to provide a plurality of parallel
bands 6, which are spaced along the width of the film 3.
The continuous zone of weakening A is thus oriented in the
direction of unwinding from the drum of the film 3 and is defined
by a linear array of perforations, a preferred embodiment of which
is set forth in the following discussion.
The zone A comprises a central line 7 of perforations A, which are
regularly spaced and aligned orthogonally to the direction D.
Two outer lines 9, 10 of perforations are situated either side of
the central line 7, parallel to the latter, at equal distance, and
include perforations 11a, 11b. The distance h between the lines of
perforations is preferably within the range between 5 and 30 mm.
The width L of the zone of weakening is preferably within the range
between 30 and 100 mm. This width L corresponds to the distance
between the outer edges of the perforations of the lines 9 and
10.
The distance f between two perforations 11a or 11b of the outer
lines 9 and 10 is greater than the distance g of two successive
perforations 8 of the central line 7. In particular, the distance f
is twice the distance g (f =2 g).
The perforations 11a, 11b of the two outer lines are aligned with a
perforation 8 of the central line 7 along a direction orthogonal to
this central line.
With f =2 g, one opening 8 in two is not surrounded by openings
11a, 11b, as can be seen in FIG. 2. The patterns created by these
perforations have an I shape, reclining horizontally in FIG. 2.
The given example of three parallel lines of perforations, with a
central line in which the number of perforations per unit length is
double, is not limiting. It would be possible to provide on each
side of the central line two or more outer lines of perforations of
greater spacing.
The perforations 8, 11a, 11b may be formed in the course of the
extrusion of the film 3, or indeed in the course of the rewinding
thereof, or indeed at the time of printing, or indeed on the
apparatus (tight packaging machine) for forming the pack.
The perforations are preferably formed by a device (not shown)
constituted by hot or cold needle rollers, with a counterpart in
the form of a cylindrical brush on which the film is supported. The
perforation needles have a diameter of approximately 1 mm and a
length of approximately 10 mm and are mounted on rotating shafts,
the film to be perforated passing between the needle roller and its
counterpart.
The precut constituted by the zone A is thus formed
continuously.
FIG. 2 shows the circular contours 12 of cans of food of the same
diameter which are mutually tangent and which define between them
empty spaces 13 in the form of stars with four arms; the centers of
the contours 12 are situated at the vertices of squares having a
side length equal to the diameter of the contours. Preferably, the
zone A covers over a succession of empty spaces 13, and the central
line 7 of perforations passes substantially at the center of these
empty spaces.
A combination is made of the arrangement of the articles within the
pack and the distribution of the zone or zones A over the width of
the film so that the zone or zones A cover(s) over a succession of
empty spaces 13. Thus, in the case where the zone A is provided
halfway along the width of the film, the number of articles in a
row orthogonal to the direction E is an even number.
The opening of the film 3 for the purpose of removing one or more
cans of food is effected in the following manner.
A pressure is exerted with a finger at a selected place or site in
therefor the zone A, for example at the level of an interstice 13
formed as a space defined by gaps between the cans where the cans
do not abut which are mutually tangent and tightly packed, to
rupture the plastic sheet initiate a tongue J (FIG. 2)of 2 tear
strip, the width of which substantially corresponds to twice the
distance f between two perforations 11a or 11b of the outer lines.
The edge of the tongue corresponding to the central line 7 will be
cut off. It is then sufficient to grasp this edge and to pull the
tongue J in the direction of the arrow T1 or T2, that is to say
along the preferred direction D of tearing, perpendicularly to the
lines of perforations 7, 9, 10 to effect the opening by cutting, in
the film 3, of a strip K, the width of which corresponds to that of
the tongue J. The traction on the tongue J is thus exerted in a
direction transverse, advantageously perpendicular, to the
direction of the zone of weakening A forming a band, and not in the
direction of this zone A put into concrete form by the lines of
perforations 7, 9, 10.
The strip K has a width which is substantially twice the spacing f
between two perforations 11a or 11b and, in practice, within the
range between 10 and 60 mm.
The heat-shrinkable film 3 undergoes thermal stresses in the course
of contraction or shrinkage. The distance between the perforations
8, 11a, 11b and their diameter are selected as a function of the
mechanical characteristics of the film 3, in order to avoid the
formation of holes in the film, which holes would join together
under the effect of the thermal stresses, while permitting a
weakening of the zone under consideration A, which will permit the
initiation of the opening tongues J.
Printing may be effected on the zone of weakening A, in particular
along the lines of perforations, in order to set them into material
form and to make them more visible. This printing will give
indications as to the movements to be effected in order to initiate
and propagate the tearing of the film 3 starting from the
perforations 8, 11a and 11b.
The solution of the invention is very easy to implement, permitting
the adaptation of the precut at any stage of the
production/conversion/utilization of the product. This solution is
complementary to the properties of the film 3 having good
transverse tearing.
The invention ensures a continuous formation of the zone of
weakening A, while maintaining the integrity of the heat-shrunk
load as compared with a discontinuous process involving indentation
of the "punch" type.
The preceding examples can be repeated with similar success by
substituting the generically or specifically described reactants
and/or operating conditions of this invention for those used in the
preceding examples.
The entire disclosure of all applications, patents and
publications, cited above and below, and of corresponding French
application 97/09404, are hereby incorporated by reference.
From the foregoing description, one skilled in the art can easily
ascertain the essential characteristics of this invention, and
without departing from the spirit and scope thereof, can make
various changes and modifications of the invention to adapt it to
various usages and conditions.
* * * * *